package main

import (
	"encoding/json"
	"errors"
	"github.com/go-chi/chi/v5"
	"io"
	"log/slog"
	"net/http"
	"os"
)

// HandleWrite checks for error in ResponseWriter.Write output
func HandleWrite(_ int, err error) {
	if err != nil {
		slog.Error("error writing response", "error", err)
	}
}

// GetFile returns raw contents of a file
func GetFile(filename string, w http.ResponseWriter) {
	fileContents, err := ReadFile(filename)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			http.Error(w, "file not found", http.StatusNotFound)
		} else {
			http.Error(w, "error reading found", http.StatusNotFound)
		}
		return
	}
	HandleWrite(w.Write(fileContents))
}

// PostFile writes request's body contents to a file
func PostFile(filename string, w http.ResponseWriter, r *http.Request) {
	body, err := io.ReadAll(r.Body)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		HandleWrite(w.Write([]byte("error reading body")))
		return
	}
	err = SaveFile(filename, body)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		HandleWrite(w.Write([]byte("error saving file")))
		return
	}
	HandleWrite(w.Write([]byte("wrote to file")))
	w.WriteHeader(http.StatusOK)
}

// GetFileList returns JSON list of filenames in a directory without extensions or path
func GetFileList(directory string, w http.ResponseWriter) {
	filenames, err := ListFiles(directory)
	if err != nil {
		http.Error(w, "error searching for files", http.StatusInternalServerError)
		return
	}
	filenamesJson, err := json.Marshal(filenames)
	if err != nil {
		http.Error(w, "error marshaling json", http.StatusInternalServerError)
		return
	}
	HandleWrite(w.Write(filenamesJson))
}

// GetDayApi returns a contents of a daily file specified in URL
func GetDayApi(w http.ResponseWriter, r *http.Request) {
	dayString := chi.URLParam(r, "day")
	if dayString == "" {
		w.WriteHeader(http.StatusBadRequest)
		HandleWrite(w.Write([]byte("day not specified")))
		return
	}
	GetFile(DataFile("day/"+dayString), w)
}

// GetTodayApi runs GetFile with today's date as filename
func GetTodayApi(w http.ResponseWriter, _ *http.Request) {
	GetFile(DataFile("day/"+TodayDate()), w)
}

// PostTodayApi runs PostFile with today's date as filename
func PostTodayApi(w http.ResponseWriter, r *http.Request) {
	PostFile(DataFile("day/"+TodayDate()), w, r)
}

// GetNoteApi returns contents of a note specified in URL
func GetNoteApi(w http.ResponseWriter, r *http.Request) {
	noteString := chi.URLParam(r, "note")
	if noteString == "" {
		w.WriteHeader(http.StatusBadRequest)
		HandleWrite(w.Write([]byte("note not specified")))
		return
	}
	GetFile(DataFile("notes/"+noteString), w)
}

// PostNoteApi writes request's body contents to a note specified in URL
func PostNoteApi(w http.ResponseWriter, r *http.Request) {
	noteString := chi.URLParam(r, "note")
	if noteString == "" {
		w.WriteHeader(http.StatusBadRequest)
		HandleWrite(w.Write([]byte("note not specified")))
		return
	}
	PostFile(DataFile("notes/"+noteString), w, r)
}

// GraceActiveApi returns "true" if grace period is active, and "false" otherwise
func GraceActiveApi(w http.ResponseWriter, r *http.Request) {
	value := "false"
	if GraceActive() {
		value = "true"
	}
	HandleWrite(w.Write([]byte(value)))
	w.WriteHeader(http.StatusOK)
}

// GetVersionApi returns current app version
func GetVersionApi(w http.ResponseWriter, r *http.Request) {
	HandleWrite(w.Write([]byte(Info.Version)))
	w.WriteHeader(http.StatusOK)
}

// ConfigReloadApi reloads the config
func ConfigReloadApi(w http.ResponseWriter, r *http.Request) {
	err := Cfg.Reload()
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		HandleWrite(w.Write([]byte(err.Error())))
	}
	if r.Referer() != "" {
		http.Redirect(w, r, r.Header.Get("Referer"), 302)
		return
	}
	w.WriteHeader(http.StatusOK)
}